Cost of debt using the approximation formula For the following $1,000-par-value bond, assuming annual interest payment and a 40% tax rate, calculate the after-tax cost to maturity using the approximation formula. O Underwriting fee $15 Discount (-) or premium (+) - $20 - $20 Coupon interest rate 9% 15 years What is the after-tax cost of financing using the approximation formula? % (Round to two decimal places.)